When sorting a list of strings containing numbers, Python’s default sorting algorithm operates lexicographically. This can lead to unexpected results, especially when dealing with measurements or alphanumeric data:

a = ['2 ft 7 in', '1 ft 5 in', '10 ft 2 in', '2 ft 11 in']
sorted(a)

['1 ft 5 in', '10 ft 2 in', '2 ft 11 in', '2 ft 7 in']

As you can see, the default sorted() function produces a result that doesn’t align with our intuitive understanding of numerical order. It places ’10 ft 2 in’ before ‘2 ft 11 in’ because it compares the strings character by character.

The natsort library solves this problem by providing natural sorting functionality that handles numbers within strings intelligently.

from natsort import natsorted

a = ['2 ft 7 in', '1 ft 5 in', '10 ft 2 in', '2 ft 11 in']
natsorted(a)

['1 ft 5 in', '2 ft 7 in', '2 ft 11 in', '10 ft 2 in']

This makes natsort particularly useful when dealing with alphanumeric data, such as filenames, version numbers, or measurements.

Link to natsort.